var time_show = document.getElementsByClassName = "time_show"
    var time_01 = document.getElementById('time_01').innerHTML

    console.log(time_01)
    var maxtime = 20 * 60;
    function CountDown() {
        if (maxtime >= 0) {
            var minutes = Math.floor(maxtime / 60);
            var seconds = Math.floor(maxtime % 60);
            maxtime--
            var msg = "请在" + minutes + "分" + seconds + "秒" + "内支付" + "   &nbsp 并在下单后20分钟内结账";
            var time_all = document.all["time_01"].innerHTML = msg;
            time_01 = time_all
            console.log(time_01)
        }
    }
    timer = setInterval("CountDown()", 1000);